Back to 240V

[stevo42]

I posted this as a reply to an old previous post but since there are not email notifications I thought no one would see it so please excuse me if thats not the case.

Update with a few observations and questions from a electrical rookie. I got my system set up 240/120, both gen sets, the ST5 and Northern 2.9 KW. We had a three day power outage and everything worked fine except I spent allot of time balancing the loads. My UPSs didn't work right and the lights flickered when reefers cycled etc... Not a big deal, I was warned about balancing loads.  I didn't need 240 for my pump so all this hassle could be eliminated if I just go back to 120. (I have a plan for 240 and the deep well pump but we'll forget that for now)  So, no problem rewiring the ST5 head, but since my northern 2.9 head is (3600RPM) 240/120 wouldn't  it be true that if I just plugged into one gen head 120 outlet to feed the system I would only be able to use half the KWs and the gen head would be drastically out of balance? hence my question about being able to rewire it for 120 only or maybe it doesn't matter?  I do have an electrician/friend checking my work but you folks have the generator part down and have been a great help on that end, thank you.

[buickanddeere]

 Was the 240V set up only 240 V with two live lines and no neutral ?

[stevo42]

"Was the 240V set up only 240 V with two live lines and no neutral ?"

There are 4 wires running from the 240v gen (s)  set to the six circuit transfer switch in the house. I plan to go back to running two circuits of 120v to the house.  I have a 3000 watt 240 to 120 transformer coming, probably today, to use on the two pole Northern and will rewire the ST head for 120 only. 

[stevo42]

Would someone take a look at this transformer and tell me if this is going to work. I want to input 240v from my 2.9, two pole gen head and feed my system 120 volts....http://www.amazon.com/gp/product/B005GHGP88/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1     A neighbor stopped by and said that sort of transformer was for "European 240 volts" and wouldn't  do what I need.   Does anyone know for sure?

[buickanddeere]

  Why not just wire the generator for 120V instead of using the transformer?

[stevo42]

This is a Northern 2.9 KW, two pole, 3800 RPM head so I was told it cant be rewired for 120v only, which would have been the way to go. 

[mike90045]

Would someone take a look at this transformer and tell me if this is going to work. I want to input 240v from my 2.9, two pole gen head and feed my system 120 volts....http://www.amazon.com/gp/product/B005GHGP88/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1     A neighbor stopped by and said that sort of transformer was for "European 240 volts" and wouldn't  do what I need.   Does anyone know for sure?

You care going to have to take the cord/plug apart anyway, the outlet may be too funky to carry 3Kw, and may have to use the salvaged plug off the cord to connect it.   it claims 50 or 60 Hz so that's not an issue.  
Volts are volts, US, UK, or AU.

3000 Watt maximum capacity heavy-duty continuous use transformer.
Converts single phase 220/240 Volts down to 110/120 Volts. Compatible with 50Hz/60Hz.
Two grounded outlet in front & back of unit (accepts 3 or 2 prong US and Euro plugs)
Hard wired with a European Shucko plug also good for Asian outlets. Durable design with a heavy-duty cord.

[stevo42]

You care going to have to take the cord/plug apart anyway, the outlet may be too funky to carry 3Kw, and may have to use the salvaged plug off the cord to connect it.   it claims 50 or 60 Hz so that's not an issue. 
Volts are volts, US, UK, or AU.

3000 Watt maximum capacity heavy-duty continuous use transformer.
Converts single phase 220/240 Volts down to 110/120 Volts. Compatible with 50Hz/60Hz.
Two grounded outlet in front & back of unit (accepts 3 or 2 prong US and Euro plugs)
Hard wired with a European Shucko plug also good for Asian outlets. Durable design with a heavy-duty cord.
 
Thanks for the reply.  the other day I went around with my "watts up" meter and added up all my wattage requirements in the house. it was well under 500 watts, those LEDs do make a big dent in the watts. So you think that transformer will work? because when the UPS man comes tomorrow I can send it back real easy and do something else if I have too.  Changing a plug I can handle if thats all I have to do. 

[stevo42]

Could the potential problem with this transformer be that since there are two 120v outlets , does that mean,  there is still two "legs" of the 240 and the full wattage still can not be drawn from one leg. The idea is not "240v in, and it (can) all comes out as one 120v circuit?  Or is it?  Sorry for what be very basic questions. 

[tiger]

From the generator source you float the neutral, IE disconnect the neutral. Feed the 240 volt legs to the primary of the transformer. Pick up the neutral from the secondary of the transformer to feed to the load. This configuration will cause the generator to see a balanced load, regardless as how the wife loads it. One must insure that the generator ground is directly connected to your panel, the transformer and the panel is properly grounded. The neutral at the generator must not be tied to ground at the generator! Good luck, remember local codes and bribes prevail.

[stevo42]

Thanks for the reply, I'll pass this on to my electrician/friend who is helping me get things changed around. My main concern now is weather the transformer I ordered, and will most likely arrive today, will work or catch fire and blow up when I try and use it. I was told the European 240 was not the same as in the US, so if this transformer .."Simran THG-3000 Step Down Voltage Transformer 3000 Watts Converts AC 220 / 240 Volt to 110 Volt"  will indeed not work I can send it back with the UPS driver and avoid a catastrophic indecent and likely divorce.  This is what my neighbor had to say about that transformer......   Does it sound correct?

 "The clue is in the words: " Converts single phase 220/240 V to 110/120 V".  It is a simple step down transformer.
 
The 220 we have in the US is NOT single phase. The 220 volts we have is for loads connected BETWEEN  the two 110 volt lines (each out of phase with the other).  "

[dieselgman]

I will not vouch for that transformer being the best overall solution, (I have never had to use such a modification for a simple single-phase power supply)... but it should work fine if kept within its voltage and specified load specs.

US 240ac is sometimes referred to as split-phase because it uses a center-tapped transformer from the supply (single-phase). 240vac IS 240vac regardless. Take a look at the discussions on this forum and do a quick web search for split-phase AC.

Perhaps this diagram will help clarify: EU vs US supply transformers are going to be different in how they are tapped for a specific voltage range. Line voltage (as well as frequency) is different.



dieselgman

[stevo42]

Thats music to my ears, thank you dieselgman, I am hopping to get this project wrapped up before next Christmas.

[buickanddeere]

 Does the generator provided two wires for each 120 winding?  For 120/240 two wires are joined to provide a neutral and each of the other wires is 120V back to neutral ?

[stevo42]

 

Both 240 plugs in the back of the generator are three conductor.